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My mother was murdered by what I call corporate and political homicide i.e. FOR PROFIT! she died from a rare phenotype of CJD i.e. the Heidenhain Variant of Creutzfeldt Jakob Disease i.e. sporadic, simply meaning from unknown route and source. I have simply been trying to validate her death DOD 12/14/97 with the truth. There is a route, and there is a source. There are many here in the USA. WE must make CJD and all human TSE, of all age groups 'reportable' Nationally and Internationally, with a written CJD questionnaire asking real questions pertaining to route and source of this agent. Friendly fire has the potential to play a huge role in the continued transmission of this agent via the medical, dental, and surgical arena. We must not flounder any longer. ...TSS

Abstract: A few cases of transmissible spongiform encephalopathies in sheep have been described in France in which the protease-resistant prion protein (PrPres) exhibited some features in Western blot of experimental bovine spongiform encephalopathy in sheep. Their molecular characteristics were indistinguishable from those produced in the CH1641 experimental scrapie isolate. Four of these CH1641-like isolates were inoculated intracerebrally into wild-type C57Bl/6 mice. In striking contrast to previous results in ovine transgenic mice, CH1641 transmission in wild-type mice was efficient. Several components of the strain signature, that is, PrPres profile, brain distribution, and morphology of the deposits of the disease-associated prion protein, had some similarities with “classical” scrapie and clearly differed from both bovine spongiform encephalopathy in sheep and CH1641 transmission in ovine transgenic mice. These results on CH1641-like isolates in wild-type mice may be consistent with the presence in these isolates of mixed conformers with different abilities to propagate and mediate specific disease phenotypes in different species.

This is provided by the statistically significant increase in the incidence of sheep scrape from 1985, as determined from analyses of the submissions made to VI Centres, and from individual case and flock incident studies. ........

Marion Simmons communicated surprising evidence for oral transmissibility of Nor98/atypical scrapie in neonatal sheep and although bioassay is ongoing, infectivity of the distal ileum of 12 and 24 month infected sheep is positive in Tg338 mice.

Studies have shown that the ''negative'' line NPU flock of Cheviots can be experimentally infected with BSE by intracerebral (ic) or oral challenge (the latter being equivalent to 0.5 gram of a pool of four cow brains from animals confirmed to have BSE).

On the other hand, this component would not be distinguishable from bovine-passaged BSE prions due to the current limits of the standard biological methods and/or the molecular tools employed here to characterize prion strains. Whatever the mechanism, the notion that a passage through an intermediate species can profoundly alter prion virulence for the human species has important public-health issues, regarding emerging and/or expanding TSEs, like atypical scrapie or CWD.

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Taken all together, our results suggest that the possibility of a small ruminant BSE prion as vCJD causal agent could not be ruled out, which has important implications on public and animal health policies. On one hand, although the exact magnitude and characteristic of the vCJD epidemic is still unclear, its link with cattle BSE is supported by strong epidemiological ground and several experimental data. On the other hand, the molecular typing performed in our studies, indicates that the biochemical characteristics of the PrPres detected in brains of our sheep and goat BSE-inoculated mice seem to be indistinguishable from that observed in vCJD. Considering the similarity in clinical manifestation of BSE- and scrapie-affected sheep [48], a masker effect of scrapie over BSE, as well as a potential adaptation of the BSE agent through subsequent passages, could not be ruled out. As BSE infected sheep PrPSc have been detected in many peripheral organs, small ruminant-passaged BSE prions might be a more widespread source of BSE infectivity compared to cattle [19], [49], [50]. This fact is even more worrying since our transmission studies suggest that apparently Met129 human PrP favours a BSE agent with ovine rather than a bovine sequence. Finally, it is evident that, although few natural cases have been described and so far we cannot draw any definitive conclusion about the origin of vCJD, we can not underestimate the risk of a potential goat and/or sheep BSE agent.

Prion strains may vary in their ability to transmit to humans and animals. Few experimental studies have been done to provide evidence of differences between U.S. strains of scrapie, which can be distinguished by incubation times in inbred mice, microscopic lesions, immunoreactivity to various antibodies, or molecular profile (electrophoretic mobility and glycoform ratio). Recent work on two U.S. isolates of sheep scrapie supports that at least two distinct strains exist based on differences in incubation time and genotype of sheep affected. One isolate (No. 13-7) inoculated intracerebrally caused scrapie in sheep AA at codon 136 (AA136) and QQ at codon 171 (QQ171) of the prion protein in an average of 19 months post-inoculation (PI) whereas a second isolate (No. x124) caused disease in less than 12 months after oral inoculation in AV136/QQ171 sheep. Striking differences were evident when further strain analysis was done in R111, VM, C57Bl6, and C57Bl6xVM (F1) mice. No. 13-7 did not induce disease in any mouse strain at any time post-inoculation (PI) nor were brain tissues positive by western blot (WB). Positive WB results were obtained from mice inoculated with isolate No. x124 starting at day 380 PI. Incubation times averaged 508, 559, 601, and 633 days PI for RIII, C57Bl6, VM, and F1 mice, respectively. Further passage will be required to characterize these scrapie strains in mice. This work provides evidence that multiple scrapie strains exist in U.S. sheep.

One of these isolates (TR316211) behaved like the CH1641 isolate, with PrPres features in mice similar to those in the sheep brain. From two other isolates (O100 and O104), two distinct PrPres phenotypes were identified in mouse brains, with either high (h-type) or low (l-type) apparent molecular masses of unglycosylated PrPres, the latter being similar to that observed with CH1641, TR316211, or BSE. Both phenotypes could be found in variable proportions in the brains of the individual mice. In contrast with BSE, l-type PrPres from "CH1641-like" isolates showed lower levels of diglycosylated PrPres. From one of these cases (O104), a second passage in mice was performed for two mice with distinct PrPres profiles. This showed a partial selection of the l-type phenotype in mice infected with a mouse brain with predominant l-type PrPres, and it was accompanied by a significant increase in the proportions of the diglycosylated band. These results are discussed in relation to the diversity of scrapie and BSE strains.

Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.

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The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease.

A The Present Position with respect to Scrapie A] The Problem Scrapie is a natural disease of sheep and goats. It is a slow and inexorably progressive degenerative disorder of the nervous system and it ia fatal. It is enzootic in the United Kingdom but not in all countries. The field problem has been reviewed by a MAFF working group (ARC 35/77). It is difficult to assess the incidence in Britain for a variety of reasons but the disease causes serious financial loss; it is estimated that it cost Swaledale breeders alone $l.7 M during the five years 1971-1975. A further inestimable loss arises from the closure of certain export markets, in particular those of the United States, to British sheep. It is clear that scrapie in sheep is important commercially and for that reason alone effective measures to control it should be devised as quickly as possible. Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates.

One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias" Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously.

SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).

Wednesday, February 16, 2011 IN CONFIDENCE SCRAPIE TRANSMISSION TO CHIMPANZEES

IN CONFIDENCE

reference...

RB3.20

TRANSMISSION TO CHIMPANZEES

1. Kuru and CJD have been successfully transmitted to chimpanzees but scrapie and TME have not.

2. We cannot say that scrapie will not transmit to chimpanzees. There are several scrapie strains and I am not aware that all have been tried (that would have to be from mouse passaged material). Nor has a wide enough range of field isolates subsequently strain typed in mice been inoculated by the appropriate routes (i/c, ilp and i/v) :

3. I believe the proposed experiment to determine transmissibility, if conducted, would only show the susceptibility or resistance of the chimpanzee to infection/disease by the routes used and the result could not be interpreted for the predictability of the susceptibility for man. Proposals for prolonged oral exposure of chimpanzees to milk from cattle were suggested a long while ago and rejected.

4. In view of Dr Gibbs' probable use of chimpazees Mr Wells' comments (enclosed) are pertinent. I have yet to receive a direct communication from Dr Schellekers but before any collaboration or provision of material we should identify the Gibbs' proposals and objectives.

5. A positive result from a chimpanzee challenged severely would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.

6. A negative result would take a lifetime to determine but that would be a shorter period than might be available for human exposure and it would still not answer the question regarding mans' susceptibility. In the meantime no doubt the negativity would be used defensively. It would however be counterproductive if the experiment finally became positive. We may learn more about public reactions following next Monday' s meeting.

Some further information that may assist in decision making has been gained by discussion with Dr Rosalind Ridley.

She says that careful study of Gajdusek's work shows no increased susceptibility of chimpanzees over New World Monkeys such as Squirrel Monkeys. She does not think it would tell you anything about the susceptibility to man. Also Gajdusek did not, she believes, challenge chimpanzees with scrapie as severely as we did pigs and we know little of that source of scrapie. Comparisons would be difficult. She also would not expect the Home Office to sanction such experiments here unless there was a very clear and important objective that would be important for human health protection. She doubted such a case could be made. If this is the case she thought it would be unethical to do an experiment abroad because we could not do it in our own country.

Retrospectively she feels they should have put up more marmosets than they did. They all remain healthy. They would normally regard the transmission as negative if no disease resulted in five years.

We are not being asked for a decision but I think that before we made one we should gain as much knowledge as we can. If we decided to proceed we would have to bear any criticisms for many years if there was an adverse view by scientists or­media. This should not be undertaken lightly. There is already some adverse comment here, I gather, on the pig experiment though that will subside.

The Gibbs' (as' distinct from Schellekers') study is somewhat different. We are merely supplying material for comparative studies in a laboratory with the greatest experience of human SEs in the world and it has been sanctioned by USDA (though we do not know for certain yet if chimpanzees specifically will be used). This would keep it at a lower profile than if we conducted such an experiment in the UK or Europe.

I consider we must have very powerful and defendable objectives to go beyond Gibbs' proposed experiments and should not initiate others just because an offer has been made.

Scientists have a responsibility to seek other methods of investigative research other than animal experimentation. At present no objective has convinced me we need to do research using Chimpanzees - a species in need of protection. Resisting such proposals would enable us to communicate that information to the scientist and the public should the need arise. A line would have been drawn.

Press reports indicate that increased surveillance is catching what otherwise would have been unreported findings of atypical scrapie in sheep. In 2009, five new cases have been reported in Quebec, Ontario, Alberta, and Saskatchewan. With the exception of Quebec, all cases have been diagnosed as being the atypical form found in older animals. Canada encourages producers to join its voluntary surveillance program in order to gain scrapie-free status. The World Animal Health will not classify Canada as scrapie-free until no new cases are reported for seven years. The Canadian Sheep Federation is calling on the government to fund a wider surveillance program in order to establish the level of prevalence prior to setting an eradication date. Besides long-term testing, industry is calling for a compensation program for farmers who report unusual deaths in their flocks.

A distinct strain of scrapic identified in sheep of Norway in 1998 has since been identified in numerous countries throughout Europe. The disease is known as Nor98 or Not-98-like scrapic. among other names. Distinctions between classic scrapie and Nor98 scrapie are made based on histopathologv and immunodiagnostic results. There are also differences in the epidemiology, typical signalment, and likelihood of clinical signs being observed. In addition, sheep that have genotypes associated with resistance to classic scrapie are not spared from Nor98 disease. The various differences between classic and Nor98 scrapie have been consistently reported in the vast majority of cases described across Europe. The current study describes in detail the patholo gic changes and diagnostic results of the first 6 cases of' Nor98 scrapic disease diagnosed in sheep of the United States.

Case I The first case identified as consistent with Nor98 scrapie had nonclassic PrP distribution in brain tissue, no PrPSC in lymph tissue, and nonclassic migration of protein bands on a Western blot test. The animal was an aged, mottled-faced ewe that was traced back to a commercial flock in Wyoming. ...

Case 2 The second case was a clinically normal 8-year-old Suffolk ewe that had been in a quarantined flock for 5 years at a USDA facility in Iowa.

Case 3 A 16-year-old, white-faced, cross-bred wether was born to a black-faced ewe. He lived his entire life as a pet on a farm in California.

Case 4 The fourth case of Nor98 scrapie was identified in an approximately 8-year-old Dorset ewe that was born into a flock of approximately 20 ewes in Indiana.

Case 5 The fifth case was a clinically normal, approximately 3-year-old, white-faced, cross-bred ewe from an approximately 400 head commercial flock in Minnesota.

Case 6 The sixth case of Nor98 scrapie was identified in a 4-year-old, white-faced ewe that was purchased and added to a commercial flock in Pennsylvania

PAGE 25 Transmission Studies Mule deer transmissions of CWD were by intracerebral inoculation and compared with natural cases resulted in a more rapidly progressive clinical disease with repeated episodes of synocopy ending in coma. One control animal became affected, it is believed through contamination of inoculam (?saline). Further CWD transmissions were carried out by Dick Marsh into ferret, mink and squirrel monkey. Transmission occurred in all of these species with the shortest incubation period in the ferret...

Clearly, it is premature to draw firm conclusions about CWD passing naturally into humans, cattle and sheep, but the present results suggest that CWD transmissions to humans would be as limited by PrP incompatibility as transmissions of BSE or sheep scrapie to humans. Although there is no evidence that sheep scrapie has affected humans, it is likely that BSE has caused variant CJD in 74 people (definite and probable variant CJD cases to date according to the UK CJD Surveillance Unit). Given the presumably large number of people exposed to BSE infectivity, the susceptibility of humans may still be very low compared with cattle, which would be consistent with the relatively inefficient conversion of human PrP-sen by PrPBSE. Nonetheless, since humans have apparently been infected by BSE, it would seem prudent to take reasonable measures to limit exposure of humans (as well as sheep and cattle) to CWD infectivity as has been recommended for other animal TSEs.

and why do we not want to do TSE transmission studies on chimpanzees $

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5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.

THE VETERINARY RECORD HAS PUBLISHED AN ARTICLE ON A NEW BRAIN DISORDER OF CATTLE DISCOVERED THROUGH OUR CONTROL MEASURES FOR BSE. ALTHOUGH IT PRESENTS SIMILAR CLINICAL SIGNS TO BSE THERE ARE MAJOR DIFFERENCES IN HISTOPATHOLOGY AND INCUBATION PERIODS BETWEEN THE TWO. MUST EMPHASISE THAT THIS IS _NOT_ BSE.

4. IS THIS NEW BRAIN DISORDER A THREAT ?

WE DO NOT EVEN KNOW WHETHER THE AGENT OF THIS DISEASE IS TRANSMISSIBLE. IN ANY CASE, CASES SO FAR IDENTIFIED HAD SHOWN SIMILAR SYMPTOMS TO THOSE OF BSE, AND THEREFORE HAVE BEEN SLAUGHTERED AND INCINERATED, SO THAT IF A TRANSMISSIBLE AGENT WERE INVOLVED IT WOULD HAVE BEEN ELIMINATED. ...

30. The Committee noted that the results were unusual. the questioned whether there could be coincidental BSE infection or contamination with scrapie. Dr. Tyrell noted that the feeling of the committee was that this did not represent a new agent but it was important to be prepared to say something publicly about these findings. A suggested line to take was that these were scientifically unpublishable results but in line with the policy of openness they would be made publicly available and further work done to test their validity. Since the BSE precautions were applied to IBNC cases, human health was protected. Further investigations should be carried out on isolations from brains of IBNC cases with removal of the brain and subsequent handling under strict conditions to avoid the risk of any contamination.

31. Mr. Bradley informed the Committee that the CVO had informed the CMO about the IBNC results and the transmission from retina and he, like the Committee was satisfied that the controls already in place or proposed were adequate. ... snip... see full text

Norway Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.

***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.

Molecular variants of PrPSc are being increasingly investigated in sheep scrapie and are generally referred to as "atypical" scrapie, as opposed to "classical scrapie". Among the atypical group, Nor98 seems to be the best identified. We studied the molecular properties of Italian and Norwegian Nor98 samples by WB analysis of brain homogenates, either untreated, digested with different concentrations of proteinase K, or subjected to enzymatic deglycosylation. The identity of PrP fragments was inferred by means of antibodies spanning the full PrP sequence. We found that undigested brain homogenates contain a Nor98-specific PrP fragment migrating at 11 kDa (PrP11), truncated at both the C-terminus and the N-terminus, and not N-glycosylated. After mild PK digestion, Nor98 displayed full-length PrP (FL-PrP) and N-glycosylated C-terminal fragments (CTF), along with increased levels of PrP11. Proteinase K digestion curves (0,006-6,4 mg/ml) showed that FL-PrP and CTF are mainly digested above 0,01 mg/ml, while PrP11 is not entirely digested even at the highest concentrations, similarly to PrP27-30 associated with classical scrapie. Above 0,2 mg/ml PK, most Nor98 samples showed only PrP11 and a fragment of 17 kDa with the same properties of PrP11, that was tentatively identified as a dimer of PrP11. Detergent solubility studies showed that PrP11 is insoluble in 2% sodium laurylsorcosine and is mainly produced from detergentsoluble, full-length PrPSc. Furthermore, among Italian scrapie isolates, we found that a sample with molecular and pathological properties consistent with Nor98 showed plaque-like deposits of PrPSc in the thalamus when the brain was analysed by PrPSc immunohistochemistry. Taken together, our results show that the distinctive pathological feature of Nor98 is a PrP fragment spanning amino acids ~ 90-155. This fragment is produced by successive N-terminal and C-terminal cleavages from a full-length and largely detergent-soluble PrPSc, is produced in vivo and is extremely resistant to PK digestion.

*** Intriguingly, these conclusions suggest that some pathological features of Nor98 are reminiscent of Gerstmann-Sträussler-Scheinker disease.

***Edited by Stanley B. Prusiner, University of California, San Francisco, CA (received for review March 21, 2005)

Abstract Scrapie in small ruminants belongs to transmissible spongiform encephalopathies (TSEs), or prion diseases, a family of fatal neurodegenerative disorders that affect humans and animals and can transmit within and between species by ingestion or inoculation. Conversion of the host-encoded prion protein (PrP), normal cellular PrP (PrPc), into a misfolded form, abnormal PrP (PrPSc), plays a key role in TSE transmission and pathogenesis. The intensified surveillance of scrapie in the European Union, together with the improvement of PrPSc detection techniques, has led to the discovery of a growing number of so-called atypical scrapie cases. These include clinical Nor98 cases first identified in Norwegian sheep on the basis of unusual pathological and PrPSc molecular features and "cases" that produced discordant responses in the rapid tests currently applied to the large-scale random screening of slaughtered or fallen animals. Worryingly, a substantial proportion of such cases involved sheep with PrP genotypes known until now to confer natural resistance to conventional scrapie. Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice. *** These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.

Atypical scrapie is a TSE occurring in small ruminants and harbouring peculiar clinical, epidemiological and biochemical properties. Currently this form of disease is identified in a large number of countries. In this study we report the transmission of an atypical scrapie isolate through different species barriers as modeled by transgenic mice (Tg) expressing different species PRP sequence.

The donor isolate was collected in 1995 in a French commercial sheep flock. inoculation into AHQ/AHQ sheep induced a disease which had all neuro-pathological and biochemical characteristics of atypical scrapie. Transmitted into Transgenic mice expressing either ovine or PrPc, the isolate retained all the described characteristics of atypical scrapie.

Surprisingly the TSE agent characteristics were dramatically different v/hen passaged into Tg bovine mice. The recovered TSE agent had biological and biochemical characteristics similar to those of atypical BSE L in the same mouse model. Moreover, whereas no other TSE agent than BSE were shown to transmit into Tg porcine mice, atypical scrapie was able to develop into this model, albeit with low attack rate on first passage.

Furthermore, after adaptation in the porcine mouse model this prion showed similar biological and biochemical characteristics than BSE adapted to this porcine mouse model. Altogether these data indicate.

(i) the unsuspected potential abilities of atypical scrapie to cross species barriers

(ii) the possible capacity of this agent to acquire new characteristics when crossing species barrier

These findings raise some interrogation on the concept of TSE strain and on the origin of the diversity of the TSE agents and could have consequences on field TSE control measures.

*** Spraker suggested an interesting explanation for the occurrence of CWD. The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr. Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at this site. When deer were introduced to the pens they occupied ground that had previously been occupied by sheep.

(PLEASE NOTE SOME OF THESE OLD UK GOVERNMENT FILE URLS ARE SLOW TO OPEN, AND SOMETIMES YOU MAY HAVE TO CLICK ON MULTIPLE TIMES, PLEASE BE PATIENT, ANY PROBLEMS PLEASE WRITE ME PRIVATELY, AND I WILL TRY AND FIX OR SEND YOU OLD PDF FILE...TSS)

To date the OIE/WAHO assumes that the human and animal health standards set out in the BSE chapter for classical BSE (C-Type) applies to all forms of BSE which include the H-type and L-type atypical forms. This assumption is scientifically not completely justified and accumulating evidence suggests that this may in fact not be the case. Molecular characterization and the spatial distribution pattern of histopathologic lesions and immunohistochemistry (IHC) signals are used to identify and characterize atypical BSE. Both the L-type and H-type atypical cases display significant differences in the conformation and spatial accumulation of the disease associated prion protein (PrPSc) in brains of afflicted cattle. Transmission studies in bovine transgenic and wild type mouse models support that the atypical BSE types might be unique strains because they have different incubation times and lesion profiles when compared to C-type BSE. When L-type BSE was inoculated into ovine transgenic mice and Syrian hamster the resulting molecular fingerprint had changed, either in the first or a subsequent passage, from L-type into C-type BSE.

In addition, non-human primates are specifically susceptible for atypical BSE as demonstrated by an approximately 50% shortened incubation time for L-type BSE as compared to C-type. Considering the current scientific information available, it cannot be assumed that these different BSE types pose the same human health risks as C-type BSE or that these risks are mitigated by the same protective measures.

This study will contribute to a correct definition of specified risk material (SRM) in atypical BSE. The incumbent of this position will develop new and transfer existing, ultra-sensitive methods for the detection of atypical BSE in tissue of experimentally infected cattle.

The TSE road map defining the evolution of European policy for protection against prion diseases is based on a certain numbers of hypotheses some of which may turn out to be erroneous. In particular, a form of BSE (called atypical Bovine Spongiform Encephalopathy), recently identified by systematic testing in aged cattle without clinical signs, may be the origin of classical BSE and thus potentially constitute a reservoir, which may be impossible to eradicate if a sporadic origin is confirmed.

***Also, a link is suspected between atypical BSE and some apparently sporadic cases of Creutzfeldt-Jakob disease in humans. These atypical BSE cases constitute an unforeseen first threat that could sharply modify the European approach to prion diseases.

Harvard Risk Assessment of Bovine Spongiform Encephalopathy Update, October 31, 2005 INTRODUCTION The United States Department of Agriculture’s Food Safety and Inspection Service (FSIS) held a public meeting on July 25, 2006 in Washington, D.C. to present findings from the Harvard Risk Assessment of Bovine Spongiform Encephalopathy Update, October 31, 2005 (report and model located on the FSIS website:

Comments on technical aspects of the risk assessment were then submitted to FSIS. Comments were received from Food and Water Watch, Food Animal Concerns Trust (FACT), Farm Sanctuary, R-CALF USA, Linda A Detwiler, and Terry S. Singeltary. This document provides itemized replies to the public comments received on the 2005 updated Harvard BSE risk assessment. Please bear the following points in mind: